The present invention relates to a method for repairing a hot-blast, long-time cupola furnace at the end of the smelting operation in the furnace by removing residual slag and relining the cupola.
It is known in the prior art to repair hot-blast, long-time cupola furnaces at the end of a smelting operation by removing residual slag and relining the furnace with fresh refractory tamping compound. In order to accomplish the foregoing, it is necessary that the furnace be cooled at the end of the smelting operation. Heretofore, hot-blast long-time cupola furnaces have been cooled by feeding water to the cupola furnace and its siphon at the end of the smelting operation. In the case of a typical size cupola furnace, the furnace must be cooled with water for at least 8 hours before the interior space of the furnace reaches a temperature sufficiently low for one to enter and remove the residual slag from the furnace. Despite the long cooling period, the residual tamping compound of the refractory lining of the cupola furnace and its siphon is at a temperature which is too high for effecting an efficient binding between the residual tamping compound and fresh refractory tamping compound used to reline the cupola furnace. As a result, in order to allow for sufficient cooling, the cupola furnace is generally out of operation for two consecutive days while being repaired. As a result of the foregoing, the efficiency of the cupola furnace is greatly reduced.
Naturally, it would be highly desirable to provide a method for repairing a cupola furnace by removing residual slag in relining the cupola furnace which does not require an excessive amount of time to be carried out.
Accordingly, it is the principal object of the present invention to provide a method for repairing a hot-blast long-time cupola furnace which is efficient and less time consuming than methods heretofore known.